1. Field of the Invention
This invention relates to an electronically controlled camera for electronically controlling a film advance motor contained therein based on the data from various data input means. More particularly, it relates to an auto load system for automatically winding the film up to a first exposable frame of the film, an auto wind system for automatically winding one frame of the film after shutter released, a film rewind system for rewinding the film into a film cartridge after the completion of exposure, and data processing for these systems.
2. Prior Art Statement
In recent times the development of automatic and electronic still cameras, such as lens shutter cameras, single-lens reflex cameras, etc. has been marvelous.
For example, control devices for controlling the focussing by an automatic range finder, flashing, shutter speed, the aperture, etc., which are all used for photographing, as well as the various devices such as for automatically loading the film when the film is loaded, and for automatically winding or rewinding the film, have been and are still being gradually and steadily progressed.
However, since the camera itself has, by its nature, limitations in size, weight, etc. whenever the functions thereof are diversified, it is a very important problem to solve, when developing, how to well build these functions into a compact camera body.
In recent times, therefore, in view of the extensive development of semiconductors, electronic control means, which are capable of performing more complicated controlling work and are yet compact, are often used instead of conventional mechanical controlling means.
Heretofore, cameras equipped with the aforementioned auto load systems have been used. These kinds of conventional cameras have a switch, for load only, which is held in the "on" position from a time when the back cover is closed until a time when the loading of the film is finished, and is.
Besides the above-mentioned cameras, there have also been used other types of cameras, which display the data of the frame number and the finish of the film rewinding procedure on a liquid crystal display panel, etc., electrically. A conventional camera of this type is provided with a back cover switch for detecting the opening or closing action of the back cover in order to clear these data when the film is taken out.
However, in case various exclusive-use switches are provided for various functions, the number of switches required in accordance with the diversified functions is necessarily increased. As a result, the mechanical structure thereof becomes complicated, and thus undesirable both from spacewise and weightwise points of view.
Further, conventional cameras are not equipped with a system for detecting whether the film is normally loaded or not. Therefore, the user is obliged to judge the film loading by the indication of a film counter which is actuated irrespective of the presence of the film.
Because of the foregoing reasons, users are unable to easily confirm even when film is not normally loaded.
Although there is known a camera which has a switch for detecting a stationary film state, the camera is insufficient for judging whether the film is normally loaded.
Next, attention is directed to the auto wind system. Conventional cameras detect the over-end of the film (wound up to the final frame of the film) by the increase of load applied to a film advance motor and the time-over of a timer set.
However, in a system such as mentioned above, the user must repeat such actions so as to turn on a shutter release switch for sending an electric current to a film advance motor and to cut the current due to time-over, since he cannot otherwise confirm the over-end state. The repetition of the above-mentioned actions causes adverse effects, such as breakage of film due to the winding force of the motor, an increase in backlash of the gear system of the film advance system, and consumption of battery power.